1. Field of the Invention
The invention relates in general to a reference voltage generator and more particularly to a reference voltage generator saving power.
2. Description of the Related Art
A conventional reference voltage generator utilizes a bandgap reference circuit to generate a PTAT (proportional to absolute temperature) bandgap reference voltage. Due to the characteristic of the bandgap reference circuit, the range of the bandgap reference voltage is limited. When a higher reference voltage is desired, the bandgap reference voltage is outputted via an extra operational amplifier. A resistor string is then used to generate a higher reference voltage according to the outputted bandgap reference voltage. However, the OP amplifier is not only very power-consuming, but also requires IC space when implemented.